Device, useful for checking low pressure system of motor car, comprises pressure sensor device arranged at pressure line of system for detecting pressure value predominating in pressure line, and device for evaluating tightness of system

摘要

#CMT# #/CMT# The device comprises a pressure sensor device (3) that is arranged at a pressure line (20a) of a low pressure system (2) for detecting a pressure value predominating in the pressure line and for providing the detected pressure value as a measurement signal, and an evaluating device (4) coupled with the pressure sensor device for checking tightness of the low pressure system by evaluating the measurement signal provided by the pressure sensor device and a predetermined parameter such as a revolution rate of a low pressure pump (103) of the low pressure system. #CMT# : #/CMT# The device comprises a pressure sensor device (3) that is arranged at a pressure line (20a) of a low pressure system (2) for detecting a pressure value predominating in the pressure line and for providing the detected pressure value as a measurement signal, and an evaluating device (4) coupled with the pressure sensor device for checking tightness of the low pressure system by evaluating the measurement signal provided by the pressure sensor device and a predetermined parameter (such as a revolution rate of a low pressure pump (103) of the low pressure system, an ambient pressure of the low pressure system and a stress of a brake booster attached to the low pressure system) using a predetermined algorithm. The device further comprises: a control device, which is formed to control an opening and/or locks of reversing valves of the low pressure system; and a device to display leakage of the low pressure system detected by the evaluating device. The evaluating device comprises units for detecting the opening and/or locks of the reversing valves, and units for storing reversing valves that are opened by detecting leakage of the low pressure system. The predetermined algorithm is based on a comparison of the predominating pressure value with a map or based on an analysis of a time course of the predominating pressure value. An independent claim is included for a method of checking a low pressure system for a motor car. #CMT#USE : #/CMT# The device is useful as a workshop diagnose unit or a security device for checking a low pressure system of a motor car (all claimed). #CMT#ADVANTAGE : #/CMT# The portable device effectively and rapidly checks leakage in the low pressure system of the motor car without using supplementary sensors. #CMT#DESCRIPTION OF DRAWINGS : #/CMT# The figure shows a schematic view of a device for checking a low pressure system of a motor car. 2 : Low pressure system 3 : Pressure sensor device 4 : Evaluating device 20a : Pressure line 103 : Low pressure pump.